Bitumen is a widely used material, but its aging behavior is only understood at a macroscopic level as hardening and embrittlement over time. To assess bitumen aging behavior in the long run, the pressure aging vessel (PAV) testing procedure was developed. However, this procedure including high-pressure and high-temperature oxidation of the bitumen has not yet been understood on a molecular level. Here, a bitumen sample and its SARA fractions, i.e., saturates, aromatics, resins, and asphaltenes, were investigated in comparison with their aged samples to study changes of their chemical compositions. Negative electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry [ESI(−)] FT-ICR-MS was used to analyze samples. The effect of aging was characterized using the aromaticity equivalent (X c), double bond equivalent (DBE), and van Krevelen plots. It was found that aging induces reduction of condensed aromatic compounds to alicyclic and open chain aliphatic compounds, while small aromatic compounds have been found to be relatively stable (or altered only slightly). Abundant alterations were detected in unaged bitumen. These changes can be assigned to resins and asphaltenes as compared to saturates and aromatics. Overall, alterations of highly condensed compounds were found to be related to aging. Furthermore, molecular series of CHO, CHNO, and CHOS fragments were more susceptible to oxygenation in bitumen, aromatics, resins, and asphaltenes as compared to saturates. In addition, molecular changes in asphaltenes showed a significant difference from classical assessment with high content of condensed aromatic compounds. Rather, the most abundant compounds in asphaltenes appear to be more saturated and apolar.

The mixed-metal oxo clusters FeTi5O4(OiPr)4(OMc)10 (OMc = methacrylate), Zn2Ti4O4(OiPr)2(OMc)10, Cd4Ti2O2(OAc)2(OMc)10(HOiPr)2, [Ca2Ti4O4(OAc)2(OMc)10]n, and [Sr2Ti4O4(OMc)12(HOMc)2]n were obtained from the reaction of titanium alkoxides with the corresponding metal acetates and methacrylic acid. Their structures are derived from Ti clusters with the composition Ti6O4(OR)8(OOCR′)8. The Ca and Sr derivatives consist of chains of condensed clusters.

Asphalt binder ageing leads to significant changes in mechanical and physicochemical properties and often to premature cracking in asphalt pavements. A polymer-modified asphalt binder is repeatedly aged through laboratory techniques, i.e. rolling thin film oven test and pressure ageing vessel. The resulting properties of the aged binder are analysed using dynamic shear rheometer, Fourier transform infrared spectroscopy, atomic force microscopy and cryo-environmental scanning electron microscopy. Rheological, spectroscopic and macroscopic properties change progressively with the level of laboratory ageing. Surprisingly, this change shows approximately a linear trend. The first ageing step has the highest impact on the property change, whereas all the following ageing steps result in similar but reduced impact. Moreover, there is a strong interdependency between different mechanical and physicochemical properties. Hence, novel insights into the mechanics of asphalt binder ageing and into the search for ageing laws for asphalt binders.

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Reaction of Zr(O(n)Bu)4 and silver acetate with methacrylic acid afforded a mixed-metal cluster with a Ag2Zr8O6 core and both methacrylate and 2-hydroxy-2-methylpropionate ligands.